DEGRADATION AND SOLUBILIZATION OF C-13, C-14 SIDE-CHAIN LABELED SYNTHETIC LIGNIN (DEHYDROGENATIVE POLYMERIZATE) BY LACCASE-III OF CORIOLUS-VERSICOLOR

During the decay of wood by the typical white rot fungus Coriolus vers icolor; Laccase III was the most abundantly secreted phenol oxidase, I n this study, we proposed a possibility of the intermediate degradatio n steps of polymeric lignin by a purified Laccase III using synthetic [beta-C-13] and [beta-C-14]lignin (DHP), When the [beta-C-14]DHP was i ncubated with Laccase III, the water-soluble degradation product forme d was about 8% of the applied [beta-C-14]DHP. The enzymic attack of La ccase III catalyzed the cleavage of the intermonomer linkages in the s ide chain structure of the polymeric lignin, In polymeric lignin metab olism by this fungus, laccase activity was closely related to the accu mulation of water-soluble degradation products.